A Dappnode user running the SSV app needs to know their operator public key, so that they can register the operator in the list of available operators at app.ssv.network .
The operator private key can be found in the file encrypted_private_key.json
It is the last field in the file, and looks like this:
"pubkey": "LS0tLS1CRUdJTiBSU0EgUFVCTElDIEt...lots of characters...0tRU5EIFJTQSBQVUJMSUMgS0VZLS0tLS0K"
Currently the only way to get the information is to back up the file from the Dappnode, save it to your local disk, then open the file and drill down through the archive to the file.
But the information is SUPPOSED to be shown on the app "info" page. There is a field for it. But currently it just says "null"
I suspect this problem might come from a change in naming. I believe the field used to be called "publickey". When this changed, that could have broken the info tab display.
Either way, this is a fairly important thing to fix, and shouldn't be terribly hard.